Fastener-driving tools, which may be pneumatically powered or combustion-powered, are used widely for driving fasteners of a type having an elongate shank with a pointed end and having a head. Typically, such fasteners are designed to be forcibly driven through a workpiece, into a substrate. Such fasteners include nails designed to be forcibly driven into wood and drive pins designed to be forcibly driven into concrete, masonry, or steel. An exemplary use of such drive pins is for attaching metal channels, which are used to mount plasterboard walls, to steel substrates.
As exemplified in German Offenlegunsschrift No. 2,524,782, it is known for a fastener of the type noted above to have an elongate shank with two portions of different diameters, namely a thicker portion adjoining a head of the fastener and a thinner portion adjoining a pointed end of the elongate shank.
In Ernst et al. U.S. Pat. No. 5,069,340, a strip of collated fasteners of the type noted above is disclosed, which employs a carrier molded of a polymeric material. As stated therein, polypropylene is a preferred material for the carrier. As illustrated and described therein, each fastener is a drive pin having an elongate shank of a uniform diameter except at a pointed end of the drive pin, and except at a flared portion where the elongate shank adjoins a head of the drive pin.
Since the driving power of a combustion-powered tool of a type exemplified in Nikolich U.S. Pat. Nos. 4,403,722, 4,483,280, and Re. 32,452, the drive pins disclosed in Ernst et al. U.S. Pat. No. 5,069,340 typically is less than the driving power of a powder-actuated tool employing a powder charge, it has been a practical necessity heretofore to employ a powder-actuated tool employing a powder charge to drive a steel pin through a steel workpiece into a substrate.
This invention provides improvements over the pins and strip of collated fasteners illustrated and described in Ernst et al. U.S. Pat. No. 5,069,340, especially in relation to the ability of pins associated with the strip to penetrate steel when driven by a combustion-actuated tool of the type exemplified in the Nikolich patents noted above.